Improvement in screw-thread counters



C. C. COLEMAN.

SCREW-THREAD COUNTER.

No. 191,315. Patented May 29,1877.

Wi ne ses nv n or' 7 MP Q W N. PETERS PHOTO-UTHOGRAPNER, WAsmNGTON D c UNITED PATENT Qrrron.

CHARLES O. COLEMAN, OF HONOLULU, HAWAII.

IMPROVEMENT IN SCREW-THREAD COUNTERS.

Specification forming part of Letters Patent No. 191,3 [5, dated May 29, 1877; application filed March 17, 1877.

To all whom it may concern Be it known that 1, CHARLES C. COLEMAN, of Honolulu, Hawaii, have invented a Screw- Thread Counter; and I do hereby declare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawings.

The object of my invention is to provide a ready and convenient means for determining the number of threads to the inch upon screwthreads of taps, dies, bolts, nuts, and other articles and it consists of a series of plates pivoted together, and having their edges serrated to represent the different threads usual to screws. Either of these plates may be turned out from the others, and by trying its serrated edge upon the threads of the screw a glance will show Whether it is the gage sought.

Referring to the accompanying drawings for a more complete explanation of my invention, Figure l is a view of my device closed. Fig. 2 is a view, showing an exterior gage. Fig. 3 is a view, showing an interior gage.

A A are two outer leaves or cases, between i which are placed as many plates 0 as may be needed or desired. These plates and protecting-leaves are pivoted at a point, D, which will allow of any one being opened out independent of the case, so as to be applied to the work.

Upon a free edge of these plates 0 are made teeth, of a shape and angle to fit screw-threads of difl'erent degrees of fineness, and the num.

the hole and fitted without trouble into the threads.

By this mechanism I provide a ready and convenient means for ascertaining at once the number of threads to the inch upon any undetermined bolt or nut, or upon taps or dies which are not marked, and the selection of the necessary counterpart is expeditiously determined.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The notched or serrated plates 0, for the purpose of determining the number of threads upon bolts, nuts, dies, taps, &c., substantially as herein described.

2. The serrated plates 0, for indicating the number of threads to an inch, said plates being united at D, so as to form a case or book of indicators of diiferent sizes, substantially as herein described.

In witness whereof I have hereunto set my hand and seal.

CHARLES C. COLEMAN. [L. s.]

Witnesses:

T. B. HASOALL, GEO. P. GAsTLE. 

